1. Field of the Invention
The present invention relates generally to an electrochemical sensing test piece, and more particularly to an innovative testing piece with a porous filter layer mounted on a reaction tank.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Currently, a blood-glucose meter detects chemical levels based on optical and electrochemical principles. Using the optical principle, color of a reagent paper changes after reaction between glucose in blood and fermentation in the reagent paper. Then, reflected rays are detected by an optical lens, creating signals that turn into a blood glucose value. Using the electrochemical principle, there is a particular and controlled chemical reaction of blood glucose to produce electrons on a sensing test piece. The electrons generated accumulate on an electrode surface of the sensing test piece, then, a fixed voltage is provided to detect the number of electrons and current on the electrode surface. Using a conversion formula embedded into the blood glucose tester, users can calculate the concentration of glucose in the blood.
However, the portable prior art device integrating the blood glucose tester and sensing test piece often make a large amount of measurement error, primarily because of the hematocrit (HCT) in the blood sample. The different effects generated by HCT include: 1) varying blood concentrations, which leads to inconsistent electronic transmission efficiency, thus affecting the final measurement; and 2) causing inconsistent volumes of serum, requiring different and changing measurement criteria.
Furthermore, the sensing test piece is structured in such a manner that a slotted groove is placed laterally onto the sensing end, enabling the user to drip a little blood sample into the groove. Then, the blood sample absorbs into this groove by siphoning, so as to generate a chemical reaction with the internally-set electrochemical reaction unit. Because of the inconsistent concentrations of serum and hemocyte in the blood of users (including: human beings and animals) when the users drip the blood sample into the groove, the sample volume of blood serum absorbed every time into the groove and fed to the electrochemical reaction unit for reaction will vary from different interferences arising from hemocyte concentrations. The different degrees of blood concentration will certainly cause variations in each reaction and inaccuracy of measurement.
The currently available electrochemical sensors based on oxidases are vulnerable to the influence of oxygen content in the samples. Conversely, it is observed that some dehydrogenase sensors are affected by other in-vivo drugs or metabolites, leading to abnormal measurements. For instance, the measurement accuracy will be lost due to the influence of drug metabolites, when peritoneal dialysis is used for the blood glucose of nephrotics.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy.
Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.